Hilary Duff gave birth to a beautiful baby girl, named Banks Violet Bair, on Thursday, Oct. 25 at her Los Angeles home.

It's the first baby for the "Younger" star and her boyfriend Matthew Koma. She shared a photo of their daughter on Instagram, with the caption: "this little bit has fully stolen our hearts!"

The 31-year-old sweetly hinted at the news on Sunday by sharing a snap of Koma playing the guitar and captioning it "Dad." A new dad indeed.

The newest addition to their family means Hilary's 6-year-old son Luca Comrie is now a big brother. Plus, Duff couldn't have been happier that she and Koma were having a girl. When she announced the pregnancy on Instagram, the former Lizzie McGuire actress said she and Matthew "couldn't be more excited" because they "made a little princess of our own." In fact, that's how the family spent Mother's Day: by having a gender reveal party.

"Luca thinks Cofant Croissant is, like, the coolest name," Duff told James Corden in June. "He told his friend at school the other day that he's having a sister that's part red-butt monkey."

In August, Duff told E! News that she doesn't "always balance it all," meaning parenting and work. "I do the best that I can, and some months are crazier than others." In early September, the parents-to-be had a sweet maternity photo shoot and she glowed from head to toe.

Even though Koma and Duff just welcomed their daughter, an engagement is nowhere in the near future for these two. A source told E! News earlier that they were in "no rush to get married." The insider explained, "They already feel married and don't feel they need a signed document to seal the deal."